<!DOCTYPE html>
<html>
        <head>
                <link rel="stylesheet" href="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/css/bootstrap.min.css">  
                <script src="http://cdn.static.runoob.com/libs/jquery/2.1.1/jquery.min.js"></script>
                <script src="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/js/bootstrap.min.js"></script>
        </head>
        <body>
            <form role="form">
                <div class="form-group">
                    <label for="inputfile">文件输入</label>
                    <input type="file" id="inputfile">
                    <p class="help-block">这里是块级帮助文本的实例</p>
                </div>
                <div class="check-block">
                    <label >
                        <input type="checkbox">请打勾
                    </label>
                </div>
                <button type="submit" class="btn  btn-default">提交</button>

            </form>
        </body>
</html>